diff options
| -rw-r--r-- | drivers/dma/pl330.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 944b67622916..0e1f56772855 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2155,6 +2155,33 @@ static int pl330_terminate_all(struct dma_chan *chan) return 0; } +/* + * We don't support DMA_RESUME command because of hardware + * limitations, so after pausing the channel we cannot restore + * it to active state. We have to terminate channel and setup + * DMA transfer again. This pause feature was implemented to + * allow safely read residue before channel termination. + */ +int pl330_pause(struct dma_chan *chan) +{ + struct dma_pl330_chan *pch = to_pchan(chan); + struct pl330_dmac *pl330 = pch->dmac; + unsigned long flags; + + pm_runtime_get_sync(pl330->ddma.dev); + spin_lock_irqsave(&pch->lock, flags); + + spin_lock(&pl330->lock); + _stop(pch->thread); + spin_unlock(&pl330->lock); + + spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_mark_last_busy(pl330->ddma.dev); + pm_runtime_put_autosuspend(pl330->ddma.dev); + + return 0; +} + static void pl330_free_chan_resources(struct dma_chan *chan) { struct dma_pl330_chan *pch = to_pchan(chan); @@ -2842,6 +2869,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) pd->device_tx_status = pl330_tx_status; pd->device_prep_slave_sg = pl330_prep_slave_sg; pd->device_config = pl330_config; + pd->device_pause = pl330_pause; pd->device_terminate_all = pl330_terminate_all; pd->device_issue_pending = pl330_issue_pending; pd->src_addr_widths = PL330_DMA_BUSWIDTHS; |